Silicon Bronze Research Articles

Local strain approach to fatigue crack formation life at notches

The equivalent strain energy method was used to predict the fatigue crack formation life of notched bend specimens with varying notch acuities in two radically different naval alloys: a quenched and tempered steel (Q1N) and an aluminium silicon bronze (ASB). A comparison was made between predicted and experimental crack formation lives, based on a DC electrical potential drop indication of a through crack of 0.05/0.06 mm. For the Q1N steel, where the microstructural features are submicron in size, predicted crack formation lives were in good agreement with experimental results. However, for the ASB alloy with a grain size of 27 μm, very conservative lives were predicted. This difference is attributed to multi-nucleation in the ASB alloy which delayed the formation of a dominant crack to beyond the length defined as crack formation.

Atmospheric Sulfidation of Copper Alloys: I . Brasses and Bronzes

Although it is widely recognized that copper alloys are subject to sulfidation upon exposure to the atmosphere, the information available on the sulfidation rates of these alloys has come largely from field exposures under uncontrolled conditions. To gain more definitive information on the rates and processes involved in atmospheric sulfidation of copper alloys, we exposed nine copper alloys (brasses, nickel‐substituted brasses, and other common compositions) to low concentrations of hydrogen sulfide in humidified air. Among the specific results are the following. (i) The resistance to sulfidation of the brasses was 50–100 times better than that of pure copper. (ii) The substitution of nickel for part or all of the zinc produces alloys even more resistant to sulfidation for low to moderate exposures; at longer exposures their behavior is mixed. (iii) Beryllium copper and phosphor bronze are somewhat more resistant to sulfidation than copper except for long exposures, when all three behave similarly. (iv) A silicon bronze sulfidized more rapidly than copper for most exposure periods. (v) Alloying copper with 10% aluminum yields an alloy with a sulfidation resistance nearly as good as the brasses. These results are discussed in conjunction with the information available on oxide growth on these alloys, and it is demonstrated that the sulfidation resistance of the alloys is quite similar to their resistance to oxidation, once an initial oxide film has formed. The degree to which the surface oxide film inhibits copper diffusion is thus reflected in the oxidation and sulfidation behavior of a given alloy. The results indicate that the performance in sulfidizing environments of equipment containing copper alloy components or parts can thus be markedly influenced by the particular alloys selected by the physical designer.

Use of industrially available aluminium‐bronze alloys for cast restorations. I. Preliminary study

Abstract— A preliminary study of the use of three industrial aluminium bronze alloys and one silicon bronze alloy for dental castings is reported. The results indicate that satisfactory marginal fit was achieved for full crown castings, and further investigation in the use of these alloys is warranted.

Upper limit for magnetoresistance in silicon bronze and phosphor bronze wire

The electrical resistivity of silicon bronze and phosphor bronze was measured in magnetic fields from 0 to 14 T and at temperatures between 2 and 300 K. At any fixed temperature, the change in resistivity to 14 T was less than a few parts in 10 5. Thus, these bronzes are excellent for use in high magnetic fields where constant resistance is required. Welding leads to the sample was found to be superior to soldering. The soldered contacts were subject to spurious resistivity changes that resulted from superconducting transitions in the solder.

ATLANTIC 13B ALLOY

Abstract ATLANTIC 13B Alloy is a silicon bronze casting alloy offering excellent castability and corrosion resistance, good machinability and medium-high strength. It is an all-purpose alloy that is suitable for gears, valve parts and marine fittings. It is especially useful in stress-corrosion environments for thin-walled parts. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness and fatigue. It also includes information on corrosion resistance as well as casting, heat treating, machining, and joining. Filing Code: Cu-307. Producer or source: Atlantic Casting and Engineering Corporation.

Resistance of a Silicon Bronze at Low Temperatures

A specially prepared silicon bronze is shown to be quite insensitive to magnetic field and temperature change at liquid helium temperatures. The temperature coefficient of resistance is of the order of a few parts per million per degree over the range 2–10 K and the change in resistance at a flux density of 1 T (104 G) is about 10 ppm.

Some Dislocation Features in Deformed Copper and Alpha Brass

The nature of the dislocation arrays in f.c.c. metals after conventional deformation has been shown to be a function of the stacking fault energy. For metals with high stacking fault energy, such as copper, nickel and aluminum, the dislocations responsible for plastic deformation appear in the form of a cell structure. When the stacking fault energy is low, cell structures are not observed. At present, there are indications that the stacking fault energy may also be important when unconventional means of deformation are encountered, as in the case of shock loading. Nolder and Thomas and Johari and Thomas observed cell structures in nickel and copper while Otte and Holland and Inman, Murr and Rose observed layered-type structures in silicon bronze and 304 stainless steel after shock deformation.

AUR-O-MET 145

Abstract AUR-O-MET 145 is a silicon bronze die casting alloy having good castability and good weldability. It is suitable for gears, valve parts and marine fittings. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on heat treating and machining. Filing Code: Cu-154. Producer or source: Aurora Metal Company.

Formation of stacking faults in polycrystalline silicon bronze under tensile deformation

Abstract The changes in the x-ray Debye–Scherrer diffraction pattern, as a function of plastic strain, have been measured for a silicon bronze (Cu–6·6 at. % Si–1·2 at. % Mn) tensile specimen. Analysis of line positions and line breadths gave the following results. The stacking-fault probability increased with extension, and near fracture (70–75% extension and about 70 Kg/mm2 stress) its value was around 0·008. The extrapolated, or ‘true’ lattice parameter, measured in the radial direction, decreased, but not smoothly. The longitudinal stress calculated, using known elastic constants and theory, from the changes in lattice parameters accompanying the plastic deformation, compared favourably with that of the stress–strain curve from a standard mechanical test. This was also true when the stress was calculated from the changes in separation of the 111–200 peaks, provided a correction was made for the effect of stacking faults. If this correction was not made, then the calculated stresses fell below the value...

The Magnetic Susceptibility of Silicon Bronze (Everdur 1010) in High Fields

The Magnetic Susceptibility of Silicon Bronze (Everdur 1010) in High Fields

Low-Temperature Thermal Conductivity of Some Commercial Coppers

Values are given for the thermal conductivity between 4°K and 273°K of six commercial coppers and copper alloys: coalesced, electrolytic tough-pitch, free-cutting (tellurium) and phosphorus deoxidized coppers, free-cutting leaded brass, and silicon bronze A. The first three show the conductivity maximum typical of pure metals; the last three show the monotonic increase characteristic of alloys. The intrinsic thermal resistance in the three purer coppers varies appreciably with the concentration of chemical impurities but is much less affected by physical imperfections. In the heavily worked copper alloys the lattice contribution to the conductivity is minor and the total conductivity is essentially the electronic conductivity as limited by the imperfection scattering.

DURONZE 609

Abstract DURONZE 609 ia tough silicon bronze having good resistance to wear and to corrosion. This datasheet provides information on composition, physical properties, microstructure, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Cu-45. Producer or source: Bridgeport Brass Company.

Dealuminization of Aluminum Bronze

Abstract Though rarer than dezincification in brass, dealuminization can occur in aluminum bronze, and such attack can constitute a failure hazard. A case of a dealuminization failure in a cylinder valve is cited. This failure was attributable to selective corrosion of the aluminum-rich phase in an aluminum silicon bronze having a duplex structure. In the process of selecting a more suitable material for the cylinder valves, dealuminization studies were carried out on samples of single and two phase aluminum bronzes which were exposed to aqueous hydrofluoric acid, the corrosive agent to which the valve failures were affixed. Alpha aluminum bronze suffered no harmful attack; the duplex aluminum bronze, regardless of its heat treated structure, suffered a selective dealuminization attack which caused a severe loss in ductility.

HERCULOY 421

Abstract HERCULOY 421, also known as Revere Alloy No. 421, is a low silicon bronze having tensile properties comparable to cartridge brass and corrosion resistance similar to that of copper This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Cu-36. Producer or source: Revere Copper and Brass Inc..

HERCULOY 420

Abstract HERCULOY 420, also known as Revere Alloy No. 420, is a high silicon bronze having mechanical properties of mild steel and corrosion resistance of copper. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Cu-24. Producer or source: Revere Copper and Brass Inc..

OLYMPIC BRONZE TYPE A

Abstract OLYMPIC BRONZE Type A is a silicon bronze designed especially for structural and engineering purposes. It has the combination of high strength, workability, and corrosion resistance. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and shear strength as well as fracture toughness. It also includes information on corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Cu-22. Producer or source: Chase Brass & Copper Company Inc..